“President Obama is deeply committed to a negotiated solution with respect to Syria, and we know that Russia is likewise,” the US’s most senior diplomat said at the UN headquarters in Geneva.

The two foreign ministers agreed to meet on the fringes of a meeting of the United Nations general assembly at the end of the month to revive peace conference talks on Syria known as Geneva Two.

ConferenceMr Kerry said he and Mr Lavrov would meet in New York around September 28th “to see if it is possible then to find a date for that conference, much of which will obviously depend on the capacity to have success here in the next day, hours, days, on the subject of the chemical weapons”.

Mr Lavrov said now that Syria, an ally of Russia, had signed up to an international agreement banning chemical weapons, all parties would work with body responsible for policing the ban “to design a road which would make sure that this issue is resolved quickly, professionally, as soon as practical.”

The US has halted a push for congressional approval for military strikes against the forces of Syrian president Bashar al-Assad to see if the Russian disarmament proposal for Syria can work.

Washington claims the Assad regime gassed 1,429 people in a chemical weapons attack on a rebel-held Damascus suburb on August 21st. Syria has blamed opposition forces for the attack.

UN weapons experts UN secretary general Ban Ki-moon said that a report by UN weapons experts on the attack, due for publication next week, would be an “overwhelming report that chemical weapons [were] used.”

The experts, led by Åke Sellström of Sweden, are not obliged to say who carried out the attack. Mr Ban declined to comment on this, though he said Assad had “carried out many crimes against humanity.”

In a separate report, UN war crimes investigators accused Assad’s forces of waging a campaign using “the denial of medical care as a weapon of war.” They said in the report that they had also found “evidence that some anti-government armed groups have attacked hospitals in certain areas.”

Russian president Vladimir Putin said that the move by the Assad regime to comply with the international chemical weapons ban marked “a serious step toward the settlement of the Syrian crisis”.

The US intends to seek UN security council agreement around Syria’s chemical weapons disarmament but faces opposition from Moscow over demands that Washington drop the threat of military action.